:O thats really expensive well did you see that lens online or local store? if local store try it and ask them how is the condition of the lens, any repair has been made something like that just to be sure.

Used but well taken care of should still be pretty good. It´s not like it wears out after two years or something like that. I got a 6 year old version (sold it when I got the 50D with the 18-200 IS) used, and it worked perfectly.

It is soft wide open (they all are). But stopped down it was pretty good for what I paid for it (160 US). If you are on a budget you can get it. Like eos550D said... How much are you willing to spend?